1. Field of the Invention
The present invention relates to a stair tread mainly for use in outside stairways of low-rise residential buildings and the like, or emergency stairways in residential and other buildings.
2. Description of the Prior Art
Conventional outside stairs and emergency stairs in buildings used for residential and other purposes usually consist of shaped steel tread plates attached to steel section stringers, with the tread plates being in the form of a shallow pan which is filled with cement. In JP-A Hei 2-149035 the present inventor proposed a stair tread in which noise is reduced by encasing the metal end plate portions of the tread with synthetic rubber.
However, in this prior tread in which only the surface is covered with the synthetic rubber, rainwater collects on the upper surface of the tread and seeps into the spaces between the tread and the stringers. This ages the painted surfaces, eventually corrodes the stringer itself, produces unsightly streaks of rust and can lead to a dangerous situation by degrading the strength of the stringers.
One solution is to pack and seal the space between tread and stringer, but sealant materials have a degrading effect on the appearance, and rainwater collects on the upper portion of packing materials. In addition, the use of sealant and packing means a corresponding increase in the amount of work and time required to assemble the structure.